...
If Me.txtCID.Tag & "" = "" Then
CurrentDb.Execute "INSERT INTO COURSE (BranchID, Course, CourseDescription, CourseLimitations) " & _
"VALUES (" & Me.cboBranch & ",'" & Me.txtCourse & "', '" & Me.txtCourseDescription & [COLOR="Purple"]"','"[/COLOR] & Me.txtCourseLimitations & "') "
Else
...